Emergent macroscopic electromagnetism in the 3-dimensional non-Hermitian double-cover Lieb model

Abstract

In this paper, we investigate the behaviors of the 3-dimensional non-Hermitian double-cover Lieb model near the band-touching points. The double-cover Lieb model is composed of two copies of Lieb configurations. Our analysis demonstrates that, near the band-touching points, the double-cover Lieb model emerges macroscopic electromagnetism, which incorporates permittivity and permeability that serve as primary causes for numerous electromagnetic phenomena. By analyzing the polarized phases of flavor and spin spaces in the double-cover Lieb model, we classify different topological phases of the model corresponding to different material phases induced by permittivity and permeability. We also discuss possible experimental schemes for realizing the 3-dimensional non-Hermitian double-cover Lieb model. The double-cover Lieb models model bears similarity to low-energy quantum chromodynamics models, extension of the non-Hermitian double-cover Lieb model could enable the exploration of even richer phase phenomena.